Regenerative repeater for multiway balanced loop repeaters



Jan. r8, 1946. w. T. REA 2,392,339

REGENERATIVE REPEATER FOR MULTIWAY BALNCED LOOP REPEATERS Filed April 24, 1945 2 Sl'leets--Sheell l4 BV few ATTORNEY Jan. 8, W. T. REA l I REGENERATIVE REPEATER FORMULTIWA`Y BALANCED` LOOP REPE'ERSl Filed April 24, 1943 2 Sheets-Sheet v2 SUPPLY lll 4 l 'l n' 1 l/A/l/.EA/T'OR W Z' REA ATT'oR/VEV y Patented Jan. 8, 1946 UNITED sifn-'rlazs PATENT oFF'IcE REGENERATW,EPETEIMTQR .WAY BALANCED LOQPBEPEATEBS Wilton T. Rea,- Manliasset, N; Y., assigxior: to Bell Telephone Laboratories, Incorporated, New

York, N. Yi, a corl'l'o'ration of New York ApplicationApr'l 24, 1943', Serial No; 484,336

Claims.

This invention relatesgto telegraph systemsfa-nd particularly to an improved multiway regenerative repeater for use in reshaping and retiming distorted signals inv telegraph systems compris.- ing a group-of telegraph lines each equipped with anindividual balanced loop repeater, Which group is interconnected'to a single regenerative repeater unit in such manner that any one of the tele.:- graph lines may transmit to all of the others comprisingy the group simultaneously.

The single regenerative repeater herein isarlranged so that itis common to the entire group of balanced loop telegraph repeater circuits. It receives. signals transmitted by any of the individual repeaters forming part of. the group, reA shapes and retimes them and transmits' them to all of the other lines' forming part of thev group simultaneously.

An object of this inventionis'- the improvement of telegraph systems which include regenerative repeaters.

A more particular object of this invention is the provision of a system wherein a single regenerae' tive repeater serves a group of three or more balanced loop telegraph repeaters in such man ner that any -o'neot the repeaters forming part ci'- the group' may transmitsimultaneously to all other repeaters formingpart of' the group.

A fur-ther object'- of the invention -is` the previsio'n of a system wherein a group of three lor more telegraph lines each including a balanced loop repeaterl is served by a single regenerative repeater uni-t and in which the regenerative Vre'- peater unitfis arranged' 'for -open andclosed op'- eration in transmitting signals from 'the regenerative repeater to the balancedloop repeaters in the group'.

A feature of thisinvention isi an arrangement wherein a single regenerative repeater unit is arranged to receive telegraph signalsA from one of a group of telegraph lines each equipped individually with a balanced-loop telegraph repeater and transmit regenerative `signals to each of the other lines vforming part of the group simul-v taneous'ly.-

A further 4feature of this invention is an ar-v rangement wherein a `rregenerative repeater de' signed Ato serve' simu-'ltaneouslya group o'fthr'ee or more balanced' loop telegraph repeater lines transmits open' and closed telegraph signalsy toward' the vbalanced lo'op repeaters;

The manner' in which the'- invention herein operates may 'be understood from the following' description when rea'dl'with'referenc'-to the' asl-vv so'cia'ted drawings in'l which;

GENERAL DESCRIPTION Refer to vFle- 1 Balanced 100D repeaters A B' and' C .are @e611 connected the ,regenerative repeater D srch )ner that any. @ne 0fL them can' .trarlsjm't signals o .each of' the others s inml.-Y` taneoslr .Although Gilly .three balanced VA1.0.61 repeaters l aire shown, it vits to be understood that' any number may be connected to the single r'egenerative rep'eater D Without limit.

Polar relays I, 2, 3 and `Il are associated with repeater n. lB olarrelays 6, l .and 8 are associated with repeater l3- Pelar relays 9, |01'. Il and l2' `are associated `with .repeater C. Polar relay 6 yor ,L01 in each of these repeaters is the transmitting relay which' transmits the' regex-1era'- tv'iealsout overfth telegraph vlines 1,6, 11 andjl; respectively. Polar relays 4. 8 .and .2 are .tlie'lrecliv g relays which receive telegraph signals yincoming `over the associated lines'."16 ,"1] anc/11.13, respectvely.

Tel apli signals' overteleg'raph lille Rivrlg rlev 4' will impress' the Signals receiving relay'llH associated with regenerative repeater D. Receiving relay will, rvifturn, im.- press thesignals on `magnet 84 in the regenerative repeater The regenerative repeater D will retirne andreshape the received signals in a marmer t9 be v.described vbelow and will transmit Qeenf-and ,Closed telegraph `Signals from Contact LUZ-simultaneously torelays 6 and I0 in repeaters Band C. Relays 6 and I0 Will, in turn, transmit simultaneously pelar senalsrom their respective gent/acts 3` andfZ-.and'tvgl and` 32 vout over Vlines 'ill/fand ylll:

In `a r sirhniflar `rinalinjersignals received from telegraph. line -1 'l' .by relay 8` f will' be regenerated ,in regenerative repeaterD and transmitted by relays 2J and. -lrllqsimultaneously Aover telegraph' lines l-6- and 518'. Signals received by relay I2' .-from' telegraph linevl willlbe regenerated byregenerative' :repeater 'D and ,transmitted simultaneously by relaysfl and Swovertelegraph lines 16 Vand. 11.

yThe invention includes means for preventing the transmission of signals received over one line, such as line 16, back over the same line after regeneration. Two relays in each of repeaters A,

' B and C, namely, relays I and 3 in repeater aA, 5

DETAILED DESCRIPTION Regenerative repeater unit generative repeater.

Inorder to condition regenerative repeater unit D for operation switch 85 is rst operated. This closes a circuit from vground throughthe contact of switch 85 and the winding of 'relay 86 to bat" tery operating relay 86. The operation of relay 86v establishes a circuit from the alternating current or direct' current supply 81 through .the right and left contactsof relay 86 to motor V98. Motorl 88 thereafter rotates continuously. The motor-driving shaft and the regenerator unit driven shaft 89 are coupled together by means of a friction clutch 90 of the well-known type. Mounted on and rigidly secured to the driven shaft l89 are three 'cam discs-9|, 92 and 95. Armature IIlI is conditioned to rotate rin a limited arc about shaft II5. The driven shaft 89 is prevented from rotation by means of a raised surface 94 on the periphery of stop cam 95 which engages the'left-hand end of the J-shaped stop arm 93, depending from and integral with armature |I. when armature I0| is in its elevated position. Y

` As has been explained, the signals received by relay 4|,V 8 or I2 are impressed on polar relay 80, which, in turn, impresses them on magnet 84 of the regenerative repeater D. DependingY upon whether the received signal elements are marky 1o4 The one-way regenerative repeaterunit D em- -erative repeater'but will function with any reing'or spacing, magnet 84 will be energized or ,84 is energized when armature IOIis presented to it; the armature remains elevated against the tension of spring I|6secured at one end to the lower portion of 4stop arm 93Vand at |the other end toaX'edpin-IH. Y 'a The sending reed |03 is secured by -means of a sleeve to shaft' H5 in such a manner that it is capable of independent rotation about shaft ||5 through a small arc so that its contact I I8 mount- Vedat the left-hand extremity of sending reed VI 03 can make with and disengageY from itsV cooperating Contact |02.V f

vrAn extension of the sending reed- .to the right of shaftl I5 is separated by means of an insulating element I04Vfrom a bar I |9-to the right-hand extremityof which is secured a latching element 98. The whole assembly comprising the contacting element |18, the sending reed |03, the sleeve surrounding shaft I |5,.the insulating element |04, bar I|9 and latching element 98 forms a rigid integral'structure. If bar `I I9 is moved upwardly in a manner to be described, contact I I8 on sending reed |03 will engage marking contact |02.: If bar I I9 isV moved 4downwardly contact IIB will disengage from contact f |02.V end of armature |0| is formed into two arms |20 and |2|, one extending upwardly and o ne downwardly with respect to bar I9I. Centered near the upper and lower extremity of arms |20 land I2I, respectively, are fixed pins |06 and |01, se-

curing springs 99'and y91, respectively. Each of these springs is attached at 'its inner end to bar H9. When armature |0I moves upwardly or downwardly the centralizing springs 91 and 99 tend. to move bar ||9' in the same direction to impart motion to sending reed I 03.

When the regenerative repeater D is in the normal stopped position magnet 84 is energized and the drivenrshaft 89 is stopped. The right-hand end 98 of bar |I9 will be latched in its upper position, as shown, by the left-han-d projection on the top arm of follower 96. Marking contact 62 is closed.

It is particularly pointed out that the regenerative repeater D is arranged to retirne and re-l shape a Vtrain of signal elements comprising a xed number of elements. The regenerative repeater D in this case is functioning in a system wherein each train of signaleIements invariably comprises sevensignal elements, namely, a starting signal element, which is always a spacing signal element, followed by ve character determining signal elements, each of which may be either marking or spacingsignal elements in any combination and a final stop signal element which is always amarking signal element. f Y

The speed of motorg88 Yis fixed so thatshaft 89 will make one complete revolution in an interval equal to the time of transmission of aV train of seven unit signal elements.V Further, cams 9| and 92 are so cut that the length of Veach regenerated signal element is the same as its length as originally generated at the distant transmitting stations.

The first signal element in any train of signal in a manner to be described, so that magnet 84 is deenergized forvthis condition. Armature |0| is movedA downwardly when magnet 84 is ldeenergized duey to tension in spring I I6. The lefthand end of stop arm 93 disengages from raised surface 94 `of stop cam 95. Driven shaft 89 rotates in `a counter-clockwise direction as indicated by the arrows.

Afdownward projection |90 on will engage the periphery of` cam 92. A short interval thereafter aprojectionon cam 9| will rotate` follower 95 through a small are in a clockwise direction about its pivot |22 against the iniiuencef of spring |23 which springv is attached at its right-hand end to the upper arm of follower 96 and-at its'left-hand end to a xed pin. Spring-,|23 is itensioned. A right-hand projection atrthe bottom of the lower arm of follower 96 engages cam 9|. A left-hand Vpro- Y jection'at the topA of the upper arm of follower the projection on the. bottom arm of follower 96 and the follower will'berotated in a counter- 'I'he right-hand armature 10| An instant later the V first projection on cam 9| will have rotated pastv clobli-'wisedirection b`y' spring (23%x 'Ph-'pfdiec'r tion on the topr 6ffoiiower 9s win engage-f they top' surface of the righte'hand end 98' oroar mi;l 1oc`liini;y the right-hand e`n`dor the bar' in" its` lowei position- As result of this contact mf will be opened. g y f Y l Bar H9' willbe rocked its lower position for aniriteriz'ai equal'- to the full-length of a spacing signal which will transmitted from contact |02 to the connected repeaters.A

Whil' tar H 9' vtill looked sj" as'- to maintain contact I-Uz open to trans'initI the spacing signal element as a start signal,I the pulse oorrespondin'g to the first character-'forming sig nai element will betransrnittd iito' the regionenA ative repeater' D; It may be either niarking or spacing depending upon the particular charac"-l ter. If it is marking the magnet s4 will encre gized. If it is spacing the magnet 84 will be de@v energized. At the niddle of the pulse,.wh'eri magnet 84 will have been properly conditioned, the first projection on cani Bzwill urge follower In!! upwardly, raising armature |01, which is thus presented to magnet 84. I-f the magnet is energized the armature IUI will be retained in,

its upper position; In.V any cse, liarl I I9 will remain looked in its lower position until the neces; sary interval for the transmission of a start pulse of proper length has elapsed; Thenonce more a raised surface on c'arn 9| will attuate follower 96 unlatching the right-hand end 98 of bar H9; If the armature ||l| has remained in its upper position spring |29 is tensioned.- As soon as bar ||9 isv unlatched it will be moved upwardly; After it has completed its upwardr movement it will be relatched.. When bar I9 moves upwardly contact |02 will be reclosed. Thus a train of signals of proper over-all length and each of proper individual length will be transmitted from the regenerative repeater D. Each signal element Whether marking or spae= ing will correspond to the received signal element. Theover-alllength of the train will be the lsame as that of the received train, except when the received train is shorter than seven unit pulse length; In the latter case,` the regenerator unit will failto stop but will transmit a train of seven unit pulse lengths in duration; The lengths 'of the individual signal elements will be determined by the spacings of the raised surfaces on the peripheriesof cams 9| and 92; In the event that successive signa-l elements are of the same nature, that is to say, in the event that successive elements` are marking or spewing, although arma'- ture IUI may move while the nature of each element is being determined, bar I I-9 Will'be locked in position while the armature is moving and the armature Will have assumed a final position for the particular element corresponding t'o that as'- sum'ed for the preceding element of the same nature before bar |I9` is unlatched and bar I-'|'9 will therefore remain in the same position yfor successive marking signalb elements or successive spacing signal elements.

As mentioned above,y the finalsigna-l element of each train is always a marking signal elementi Magnet 84 rwill therefore bejnerg-zed and armature |'|l| will be retained in elevated `position for this condition.- When follower 9F -l'atche's the right-hand: end sa'. or bar i 9, bar t le wi-u be se l torted sig-nalleine'rits itis advisalile to usethe center portion of the element.` delay' isl thus interposed-,A but since allsi-gnal transitions are delaye'dan equal amount the* coniiguration ot the..

ilo

niatei'r'forie the duration of a sigaar. oieriierit clement is used tof determine the nature of eeen' 1 element.. The reason for4 thi's'is that; emerito' correctly determine the nature or' greatly dis--v signal train is: unaffected as thestart of trains: mission of each full length signal element,4 as transmitted by the' opening and closing of contact |02 of the' reg'eiierativel repeater- D, is mease ured from the receptionv of the middleportion of each signal element.

Description of operation of circuit per Fig'. 1

The opera-tion of the circuit per Fig. l will now bedescrib'ed in detail.. The condition of the various relays rwhen normal and awaiting transmission from some line forming part of the intercommunicating group will lrst be explainedl The armature of relay 2 is shownin engagen ment with contact I6.y For this condition a circuit may be, traced from positive battery through resistance 44,- contact ltand the armature of relay 2 to a parallel circuiti One branch`A of the` circuit extends through the upper windings ofv polar relaysl 3 and A4 in series lthrough resistance 48 and conductor 'I6 ,to the distant station, no t shown; At the distantstation it extends through the winding oi a receiving relay tonegative battey connected. to the marking Contact of a sendingrelay. ,The secondbranch of the parallel circuit extends through the bottom windings of polar relays 3 and 4 series and through resistance 4i to ground. The effector the current flowing through the bottom windings of relays 3 andl te'nds to actuate the armatures of relays 3 and 4 toward the left to engage their respective spacing contacts |`1 and is, This eiieot is opposed by' the current flowing thiflildtlie t'p windings f mais 3 and a, The eneot of the current flowing; Jthrough the top windings of' relays 3 and 4 is dihi'ant andthe armatures of" rrelays l3` aiid4 are maintained in eil'iigeiit 'their righthaid contacts I8 and 20, respectivly A cii'ut in the Aforni f a potentiometer may be traced frein negativo l battery through resistancje 46 to parallel branches. One branch entends through the armature and right-hand or niarkiri'g contact I4 of polar relay l' and through resifs'tailc'e's 39, 4U a'ndtl iii 'sries to positive' battery' 42. Attention is called to the' fa'ot that the posi-l tive and negative batteries 'in this circuit are arranged ih lseries aiding relationship. From the left=hand terminal of resistance '4t a branch of the circuiteitelnds' throughqcont'act I8, armature of .polai' relay 3, resistance 'liti'k and the top` of polar relay l 'to ground. Fr'o'r'n `the junction or resistances 3,9 and A|||ll a vcircuit. extends through the t'p winding 'of polar relay 2 to ground. potential between the ll-eitunan-' 1 'termi-nal otre-'- sistance 46- aiid ground and 'thev direction of the flow of current through the top Winding o'f 'polar relay is such that the 'armature of polar relay 5| is maintained in engagement with its right-hand Contact I4 orthis condition. The lcircuit through the bottom winding of polar relay V4| `'is 'open 'at Contact I3.

'l A circuit may be' tiabeti from 'positive bttey 69 through resistente 15|, bottom Winding of' polar sented abete interooses o fixed' ceioyi or apo-reine relay2, conductorV |08, bottom winding ofV polar relay 6,-,contacts |02'and |I8, sending reed |03,

conductor |09, bottom winding of polar relay IY and` resistance 13 to-ne'gative battery 15. YThe current flowing in this pathA tends to actuate the" armatures of relays 2, 6 a-nd I0 to engage with their right-hand or marking contacts I6, 24 and 32,`jrespectively. Y This elect is opposed Yby the effector currentflowing through the top wind-` ings. of relays 2, B 'and I0 which effect tends to actuate the armatures of these relays toward the left to engage with their left-hand or spacing contactsA I5, 23 and 3|, respectively. The e'ect ofthe current in the bottom windings is dominant, however, and the armatures are maintained in engagement with their right-hand orV marking contacts. The eiects of the currents in the various other windings of the relays in repeaters VB and C are the same as described for repeater A.

A circuit may also be traced from'positive battery 69 through resistance 10, contact 28, armature-of relay 4, contact-28, armature of relay 8,

the bottom winding of relay 80 remains closed.

While contact 8| is closed, a circuit may be traced from' positive 'Y battery through resistance 19, armature Yof Arelay 80, contact 8|, resistance 82 andthe winding of magnet'84 'to ground energizing magnet 84. If contact 20, 28 or 36 of receiving relays t, 8 or I 2, respectively, is opened in a manner to be described, the bottom Winding of relay 8|) will -be deenergized. The armature of relay 80 will be actuated to the left opening contact 8| and deenergizing magnet 84.

Let it be assumed that the armature of the sendingrelay at the distant station connected to conductor 16 is either open or connected to positive battery for' the transmission of a spacing signal, so that no current ows throughV the tcp windings of relays 3 and 4. The armatures of relays 3 and 4 willbe-actuated to engage their left-hand or spacing contacts I1 and I9, respectively, under the influence of current in their bottom windings. This results in the opening of contacty 8| as heretofore explained. When contact 8| is opened magnet 84 is deenergized and armature |0Ijis released to initiate the starting signal element as heretofore described.

yWhen the armature of polar relay 3 is actuated to the left in response to the receptionA of the first spacing signal element a circuit is established which may be traced from positive battery through resistance 4I, contact I1, armature of polar relay 3, resistance 45 and the top winding.

of polar relayrl to ground. VThis reverses Ythe eect of the current owing through the top,V

tery through resistance, armature ofrelay I,

contact` I3', bottom winding f relay I', and resist-l,

ances 31 and 12 inseries to ground.

The openingr ofA contact I4 of polar relay reverses theeiect of the current flowing through the top winding of polar relay 2. As a Vresult of this the armature of polar relay 2 will be maintained in engagement with its marking contact I6 when regenerated signals are transmitted from regenerative repeater D in a manner to bedescribed. Y

When, approximately a half pulse length later,

transmitting contact |02 .of regenerative repeater D is opened, the path through the bottom windings of relays 2, 6 and I0 is opened. If the direction of current ilowing through the top windings of these relays remains unchanged the armatures of these relays will be actuated to the left to transmit a spacing signal over the associatedk line. However, in the case of repeater A which is receiving a spacing signal over conductor 16, the direction of the'current flowing through the top winding of relay 2 has been changed, as described,so that the armature of relay 2 is maintained in engagement with its right-hand or marking contact I6. Thearmatures of relays 6 and I0, however, will be actuated toward the left to engage their respective contacts 23 and 3|. As a result of this the polarity of the voltage connected to the armatures of` relays 6 and I0 is changed. Negative battery is connected through resistance 5| and contact 23 to the armature of relay 6. Negative battery is also connected through resistance |24 and contact 3| to the armalture'of relay III. Spacing signals are therefore transmitted over lines 11 and 18, respectively, to the distant stations connected to repeaters B and C. The armatures of relays 1, 8, Iland I2.

will be maintained in engagement with their respective contacts =26, V28, 34 and 36 due to the reversal of the effect ofthe current in their bottom windings.

Since the armature of` relay 2 in repeater A is maintained in engagement with its contact I6 the spacing signal transmitted by regenerative repeater D in responseto the spacing signal received over conductor 16 cannot'be retransmitted by repeater A toward the distant Vstation connectedto conducto-r 16.Y

The circuit will remain' unchanged until the next marking signal element is received. When the distant end of conductor 16 isagain reconnected to negative battery to transmit a marking signalV element toward repeater A the armatures of relaysY 3 and/4' will be actuated to freengage contacts I8 and 26, respectively. The armature of relay I willbe maintained in engagement with its contact I3 and the armature of relay 2 will be maintained inengagement with its contact I6. The reclosingof contact 2Ilv of relay4rwill reenergize the bottom winding of relay 8|).v Contact 8| will be reclosed. Magnet`84 will be reenergized. About a half pulse length later contact `|02 will be reclosed- The armatures of relays 6 and I0 will be actuated to reengage theircontacts 24 and 32, respectively. As a result of this a marking signal will be transmitted over conductors 11Y and 18. The marking condition will be maintained for conductor 16.A It is particularly pointed out that after the reception of the rst or startingV signal element which is always a spacing signal lelement the succeeding iiveV signal elements may be either marking or spacing in any combination and the signals received by polar Vrelai7 4 and retransmitted from contact |02 of regenerative repeater D will depend upon the particular char- Station connected. toI repeater A. stops.. transmit.-

ting', station connected. toI repeater R starts transmitting, Fig.. 1,

In describing the operation. of repeater A above itwas explained that as soon as the first spacing signal element is received' over conductor 7:'5 the armature of relay I1 is=lockec5t in engagement with: its contact t3. Further, it: was fex plainedI that as a result. otthisthe direction of the flowofy current through. the top. winding of relay 2: was changed; from its normal direction so that itsf ei'ecttended'sto maintain.- the armature of' relay 2- in engagement with contact. I6 during n the entire interval while 'signalsv were `received. by repeater A over conductor-128; During the re.- ception of regenerated marking' signal' elements by relay i! the ellecty of the current in both the top and bottom windings of'relay'isin-thefsame .1

direction sor that for a marking signal element the armature of'relay Zismantalnedagainst its contact I by the effect ot the current in. both windingsA For a spacing signailel'ementfthe effect of the current in. the top;winding alone performs t this function as. no1 current ows through the bottoni winding.

Yt is: particularly pointed out. that asy long,- as reception of signals by repeater A over conductor 1E continues and when receptionl is terminated; unlessl there hasbeen an; interruption by thereception of a breaking signal over conductor Tt or '18, the armature of relay. l1. will remain locked in engagement with contact lf3l and'v the varma-- ture ofrelayv 2` will'. be maintained in engagement vwith contact I6.

It will be assumed" that the. reception of signals over conductor 1B byl repeater A. is terminated and that. some otherstation connected to one of the other repeaters such as' the station connected byfconductor Tt to repeater Bi starts: to transmit. In response to` theI reception ot the first spacing signal over conductor 'ITS the-armatures: of relays l and 8 will be actuated to` engage with their contacted-5 and 2li, respectively, inthe same manner as described for-'relaysv 3c and t in repeater A. In response to this the armaturel of relay 5 will be actuated to engage with its contact 2-I-. The direction of the current flowing through the top winding of rela/yf 61 will thereupon be changed so that its eiect maintains the armature of relay 6' in engagement with contact 24. When the armature-of relay 5 engages withy con-tact 2l thecircuit extend-ingr fromnegative battery through resistance 46, armature of relay I, contact I3, bottomV winding of' relay I, resistance 3'!L andcon-l ductor H3 to the top termina-1 ofresistance 'I2 is shunted? by the path extending from-.negative batteryI through resistance 58, armature or relay 5', contact 2li, bottom windingI of relay 5, resistance 49 and conductor II I tothe top terminal' of resistance 12. As av result of this the current through the bottom winding of relayl isgreducech As a result of this reduction, `the eiect ofthe current flowing through the top winding ot'relayl I 'becomes dominant-over the.. effect or theL cur.- rent through the, bottom winding of relay I: and the armature ofrelay l will be actuated to reengage with its contact I4". As the armature of relay I leaves 'contact I3 the current in thebottom winding of relayA 5 will increase locking the armature of' relay l in engagement: with contact 21.'.` y

When the armature of relay I` reengages with contact I4 the direction andmagnitude of the current. flowing' in relay Z are restored to their original conditions. That is tosayf, the effect of the current owing through thetop Winding of relay 2 tends to actuate the armature of relay 2 to engagewit-h its contact I5-. The currentwill therefore be eiective to actuate thea-rmature of relay 2 to engage with contact I5 when the-reis no current in thebottom Winding of relayqZsWhich is the condition when Contact I 0-2 of regenerative repeater D is open. In other wordslrepeaterA is conditioned to transmit-'regenerated signals over conductor; 'I6 in response to signals received: over conductor 11 `byrepeater-B; Relays t, '5 and' 9 are highV speed polar-- relays. Condensers 38, 50 and 6 lv shunt resistances'31-; 49 and Si), respectively.v Each of these resistances is in series'witha 'bottom winding o1 the high speed ,polar'ljocking relay' in each repeater. When any of the relays,y such asl Ii, 5- and 9, is locked and the armature off another of these relays' is operated to engage its spacing contact, not only is the current through thebottom winding'I of! the original locked relay reducedby theshunting-` effeet of the second', but a surge of current dueto the shunti'ng condenser is Ipassed through the bottom winding of they original locked: relay. Its eiect isy to speed the unlocking offthe relay.

Station connected to.. repeater A is transmitting and4 station connected to repeater B breal, ;,s Fig, 1

It will now be assumed that the distantstation connected to repeater A over conductor Isis still transmitting to repeater A and that another station', forinsta-nce, the station. connected to repeater B byt conductor A1T, starts tor transmit to repeater Bi If' this breaking operation occurs when'a marking signal is being received' by refpeater rA the operation'will be` the saineL as described `above-for the condition.- Wherein repeater B starts to receive from line 'l1- after receptionv by repeater A from line'lls has terminated'. But the condition wherein the other station, such as the station connected to repeater Bf by conductor 1:1, starts to transmit while repeater A is receiving a spacing signal from conductor '126.- is difterent and will now bes-explained.

During a breaking operation, say by repeater B, if a spacing signal'isbeing received 'the instant by repeater A from its. distant station,

'which has theretofore been transmitting, the are mature of relay 3' in repeater A will' `be iny engagementwith its contact I1. The eifect of' the current; nowing through the topwindingA of the relay I for this conditionras has been explained, tendsto actuate the armature of relay l to en gagewith its contact I3; Therefore, ifa spacing signal Yis 'being received by repeater A over line 'I6 when the breaking signal is received'from repeater B, the armature ofrelayA yI willbe maintained in its locked condition against contact I3 until the next marking signal element is received over line 'I6 by relay ,3, When, -nrcsponse to this, the armature of relay 3 is actuated toA engage its marking contact t8, the directionand effect: of

in engagement with its right-hand or marking contact. This applies equally to relays204 and interrupt signals vincoming over conductor 16 until the next marking signalis received over conductor 16. In this respect the system herein resembles other half duplex systems.

Embodimet per Fig. 2

I VVFig. 2 shows ,another embodiment of the invention herein. In this embodiment only three relays are required in Veach repeater instead oi?l thev four relays shown in each repeater in the embodiment per Fig. 1.v The regenerative repeater D operates in the same manner as described for the embodiment per Fig. l.

The three relays in Yrepeater A, in the embodiment per Fig. 2, are relays 20|, 202 and' 203; in repeater B, relays 204, 205 and 206;V in repeater C, relays 201,208 and 209. Relays 203, 200 and 209 are the relays which receive signals incoming from the distant connected station. Relays 20|, V204 and Y201 are therelays which Ytransmit toward the distant station. Relays 202, 205 and 208 in repeaters A, B and C, respectively, perform the function of preventing the retransmission of signals received by a particular repeater fromY its distant `associated station back toward the transmitting station. These relays function also to prevent mutilation ofthe lfirst portion Iof a, signal element whichY is being transmitted toward -the `last distant station which has been transmitting. EachV of these relays, therefore, performs the function for which two relays are required in the embodiment per Fig. 1. That is to say, relay 202, for instance, in Yrepeater A, Aper Fig. 2,y corresponds in its function to relays I and 3 in repeater A per Fig. 1,. Theoperation of Fig. 2 may be generally understood from the description of the operation of Fig. 1 above. Its operation willV be described therefore only in so far as it is necessary to'point out the distinctions in the two embodiments. The currentv conditions and their effects inthe various windings of the, relays in the embodiment per Fig. 2 Will rst be described.

A circuit may be traced from positive battery* 2I0 through resistance 2I I,' bottom winding of relay'20l, bottom winding of relay 204,'contact 2'I2, conductor 2I3, bottom Winding of relay 201, and resistance 2I4 lto negative battery 2I5. The effect of current flowing through the bottom winding ofrelays 20I, 204 andy 201 tends to ac tuate the armatures of theser relays to engage With their respective right-hand or marking contacts; Y A circuit may. also be traced in each re' ing of relay 20| to ground. The effect of currentY iiowing through the A topV Winding of relay 20| tends to actuate the armature of relay 20| toward the left. The effect of the current iiowing in the bottom winding of`relay20I is dominant, howlever, and the armature of relay 20! iS mfintfnd ',201 in repeaters B and C, respectively. When the armature of relay 20I is in engagement with its right-hand contact, a circuit may be traced from positive battery 223 through Yresistance 224 and the armature and right-hand contact of relay 20| to parallel branches. .One branch extends through resistance 225, bottom winding of relay 203 and resistance 226 to ground. A second Y branch extends, through resistance Y221 and the top Winding of relay 203 to conductor 228. Conductor' 228 extends to a telegraph repeater in a distant telegraph station, not shown. It extends through the Winding of a receiving relay and the armature of sendingrelay and is terminated in negative battery connected to the marking contact of the sending relay. The effect of the current owing through the bottom winding of relay 203'tends to actuate the'armature of relay 203 to engage with its left-hand or spacing contact but the eiect of the current flowing in the top Winding ofrelay 203 tending to actuate the armature of relay 203 towards its right-hand or marking contact is dominant and the armature is maintained in engagement with its right-hand or' marking contact. Y

The top and bottom terminals of the top winding of relay 202 are connectedto the right-hand terminals of resistances 221 and 225,.respectively. 'I'here is a diierence in potential between these terminals and theeiect of the resultant current through the top winding of 'relay 202 maintains the armature of relay 202 in engagementwith its left-hand contact for this condition. 1

It Will now be assumed that signals are transmitted from the distant station connected to repeater A. In transmitting spacing signals from the Adistant kstation toward repeater A thearrria-rv ture of the sending relay at the distant station is .connectedy either to positive `'battery or to an open circuit so thatV no current flows in the'top wind'- ingYof relay 203.A As a result of this the arma` ture of relay 203 Will be actuated toward the left under the influenceof current owing through its bottom winding. This results in the transmission of a spacing signal into regenerative repeater D in the same manner as for the embodiment per Fig. l. The transmissionY of a spacingr signal from theV distant station connected to repeater A also Veffects a reversal in the direction of. current through the top winding of relay 202 and the armature of relay 202 is actuated to engage its right-hand contact 229. A circuit may thereupon be traced from positive battery 2I6, through resistance 2 I 1, armature and contact 229 of relay 202, bottom Winding of relay 202, resistance 230 and resistance 23| to ground. The effect of this vcurrent locks the armature of relay 202 to contact 229. -When the armature of relay 202 breaks from its contact 2 I 8 the polarity of the current flowing through the top Winding of relay 20! is reversed and its effect is thereupon changed so that it tends to actuate the armature of relay 20| to engage with its right-hand contact. When transmitting contact 2I2 of regenerative repeater' D is opened to transmit the regenerated spacing signal an interval equal in duration to at least oneits marking contact. It will, therefore, beim-V possible to transmit the regeneratedsignal back towards its 4originating .source in the ldistant ofl:lice .connected toconductor 228. .Relays V204and 201, however, which correspond to relay 20.! will respond to the spacing signal under the .iniiuence of .the "current flowing through their respective f top vwindings .and their respective armatures will ductor 228 ceases to transmit the armature .of

relay Y202 will remainlocked :in engagement .with its right-.hand .contactI .229 and the current through the top winding of relay 20| will consequently .be maintained in a ldirectionsuch that its armature is maintained in engagement with its right-.hand or marking contact. If .under these circumstances a vsignal is transmitted .from `the distant station connected to .repeater B or nrepeater C the armature of relay 206 or v209 will loe actuated to engage with its ,left-hand or spacing contact, transmitting a spacing .signal into the regenerative repeater D. Simultaneously the armature of relay 20.5 or 208 will `he actuated to the right to engage with its right-hand contact. The corresponding sending relay 204 or 201 will be conditioned Ldue to the change in the direction of the current through its top Winding so that its varmature is maintained in engagement withits right-hand or marking contact. The effect of the operation of the armature of either relay 205 or 208 to engage "its right-'hand contact is to establish a shunting path for the path extending through the bottom lwinding lof relay 2'0'2, thus reducing the current flowing `through the 'bottom winding of relay v202. The eiect of the reduced Acurrent 'flowing through the bottom winding of relay "202 tending to maintain the armature of `relay 202 in engagement 'with contact 22'9 is less `than the `opposing effect ofthe current flowing through the top winding of :relay '202 and the armature `of relay 202 is operated to the left to locking current through the bottom windings 'of v.

relay 1202, 205 or 208 when any of these relays have been locked and the armature of any other of these relays vis subsequently operated to--engage with its respective locking contact.

Breakingcperation per Fig. .2

.It will be assumed that signals are 'incoming over line 4228 to repeater A in Fie. 2 and that the station connected to conductor i123! breaks, that is, starts to transmit. vIf the break occurs when a marking signal is being received over conductor 2,28 the `operation `.is the :same as :described under the preceding heading. It. however, V.the oper-e ation y.occurs when a spacing .signal element is being received over lne1228 the effect of fthecurrent in the top winding .of relay :2102 will be in a direction to actuate'the armature-:ofrelayw -toward its locking contact 229. The lhrealcwill :not occur, therefore, until a marking signal is being received by relay 202 and its effect is tending to operate the armature of relay 202 toward contact yleast three 21.8. This effect will bedominantoverthereduced effect Vof the current in the bottom winding of relay v202 tending to maintain .the `locked `.condition and the .lock will be opened. The armature of relay 202 will engage contactl'Z-I. The polarity -of the current the top -Windingof relay .20:I`

will -be vreversed and repeater A will be conditioned 'to transmit over conductor 228.

Whatis claimed is:

`1. vIn a telegraph communication circuit, at telegraph .lines interconnected throng-h .individual repeaters tto `a .single one-way regenerative repeater common to al1 of said lines, -means iin said circuit for regenerating signals-incoming from' any one of saidlines in` said regenerative 4repeater .and transmitting them simultaneously to :more than one kor" the others, a telegraph :signal receiving relay `in each `of .said indi- 'vidualrepeaters 4a contact on :each of said relays controlled .by reach of said relays, and .a single -common path extending'thrnugh Vall of :said contacts iin Vseries .to the input 4ci said regenerative repeater.

:2. In a telegraph .communication circuit, :at `least 'three telegraph lines interconnected through `individual -repeaters to .a single one-way regenerative repeater common to all of said lines. means in said circuit for Vregenerating signals "in,- coming from any one of said lines in said regenerative repeater and transmitting them .simultaneously to more vthan cneaof the others, a telegraph signa1 sending relay :ln Teach yof saidindi- Aincoming from any `one of :said .lines 'in said-1regenerative repeater, 4and transmitting them simultaneously to more .than one of the others, .a telegraph signal receiving relay .in -each of said individual repeaters, a .Contact on each of said relays, a. single common path extending through all of -sai'd contacts in :series tothe input -cf said regenerative repeater, a 'telegraph signal .transmitting Arelay in reach of said `individual repeaters, a winding .on each `of said receiving `relays and a single Icommon path `extending through .all of said windings in series to the output of .said Iiegener-ative repeater.

4. In a telegraph communication circuit, .at least three telegraph :lines interconnected through individual 4repeaters #to a single one-way regenerative repeater-commontoall of `said lines, means in said circuit for .regenerating .signals incoming from .any =one of .said lines in .said regenerative repeater and transmitting `them simultaneouslt7 to .more .than one .of the others, 1a receiving relay in each-oi said indivi-dual repeaters, alcontact .on each of :said relays, asingle :common path :extending :through all of .sai-d contacts .in series tc the input of v.said .regenerative repeater, a telegraph signal transmitting relay in teach `ci said individual repeaters, .a winding l.on :each tof said transmitting relays., :a single .common 1vpath extending through 4.all 'of said windings in senes to the zoutpnt .of said regenerative repeater, and means `in said .repeaters for preventing the r-e-r transmission `:of received through a* parsame individual repeater.

l Y 5.V In a' telegraph system, at leastV three telegraph lines each comprising an individualrepeater connected to a single one-Way regenerative repeater arranged to serve all of said lines in common, means in said system for repeating signals received from any one of said lines through said regenerative repeater, to all of the other linesy simultaneously, telegraph signal lreceiving means in each of said individual repeaters, a single common path extending through all of vsaid receiving means in series to the input ofV said regenerative repeater,telegraph signalV transmitting means in each of said individual repeaters, a single common lpath extending through all of said transmitting means in series to the output of said regenerative repeater, and means in 4each of said individual repeaters for preventing the mutilation of the rst signal element transmitted through said system Whenever the transmitting path through saidsystem ,is changed.

6. A multiway regenerative telegraph repeater system, a single common path extending through individual telegraph signal receiving elements in at least three individual repeaters'in said system all in series to the input of a single one-Way regenerative repeater, and means for transmitting telegraph signals received from any one of said individual repeaters to more than one of the others simultaneously.

7. In a telegraph system, at least three telegraph relay repeaters interconnected through a single one-Way regenerativeV repeater, means in said system for receiving signals from any one of said relay repeaters Vand repeating regenerated signals from lsaid regenerative repeater to all others of said relay repeaters, a single common path extending in series through contacts on telegraph receiving relays in each of said relay repeaters to the input of said regenerative repeater, a single common path extending in series through windings of transmitting relays in each of said relay repeaters to the output of saidregenerative repeater, a relay locking circuit for preventing the retransmission of signals received by one of y 'said relay repeaters back through the same repeater and a high speed unlocking circuit connected to said locking means.

' 8. In a telegraph system, a first, second, an

third balanced loop telegraph repeater each connected individually to a telegraph line extending to a distant station and all connected througha single common continuous path in series to a single regenerative repeater, means for receiving telegraph signals in any one of said balanced loop repeaters from its associated connecting station, means for impressing said received signals onthe input of said regenerative repeater, and

means for transmitting regenerated open and closed circuit telegraph signals from the output of said regenerative repeater to the other tWo of said balanced loop repeaters simultaneously.

9. In a telegraph system, at least three balanced loop telegraph repeaters each connected to individual telegraph channels extending to distant telegraph stations, means comprising a single continuous common circuit for connecting all of said repeaters in series to a single regenerative repeater, means for receiving signals in any of said balanced loop repeaters and impressing them through said circuit-on the input of said regenerative repeater, means for transmitting open and closed telegraph signals from the output of said regenerative repeater to all of said balanced loop` repeaters, simultaneously, and means for `transmitting polar signals in response to vsaid regenerated signals from all except the one of said balanced loop repeaters from/Which Vthe original signals were received. Y l

l0. In a telegraph system, a'multiway regenerative telegraph repeater system, a single common continuous path extending in series through individual telegraph signal receiving elements in at least three individual repeaters in said system Y to the input of a single one-way regenerative repeater, means for transmitting telegraph signals received from any one of said individual repeaters to more than one of the others simultaneously and a locking circuit comprising individual branches connected in parallel to a relay in each of said individual repeaters for preventing theretransmission of signals received from a particular.

ing regenerated open and closed signals on the other two of said line repeaters simultaneously in response to said [impressedV signals. y

12. A multiway regenerative repeater system, at least three line repeaters therein individually connected intermediate three telegraph lines and a single regenerative repeater mechanism,fmeans in said system, comprising a first single continuous circuit extending through a contact onfa receiving relay in each of said line repeaters and through a winding onV a receiving element in said mechanism, for receiving telegraph signals from any of said lines through its individual repeater and impressing them on said mechanism and means in said system, comprising a second single continuous circuit extending through a winding on a transmitting relay in each ofsaid line repeaters and through a transmitting Contactin said mechanism, for impressing regenerated signals on all of the other of said lines through their individual repeaters in response to said signals impressed on said mechanism. ,Y Y.

13. A system in accordance with claim 12 including, in combination, a device for increasing the speed With which a line which is transmitting into said mechanism is conditioned toY receive signals when another line begins to transmit into said mechanism. l

14. A system in accordance with claim 12 including, in combination, also a device forspeeding the reversal in direction, oftransmission of said line repeaters, said device comprising, in each of said line repeaters, ar first relay, operating in unison with a receivingy relay, and asecond relay,

responsive to said iirst relay, for controlling a Yfrom any line connected to saidV line repeaters and a transmitting Vrelay in each line repeater directly responsive to its corresponding said one control relay.

` WILTQN T. REA. 

